How to avoid global variables in Javascript - https://www.youtube.com/watch?v=hQVTIJBZook#t=1679

no_global.js

/**
 * Avoid Global Variables
 * ========================
 * One easy way to avoid global variables in javascript
 * is to use closures. This is a best practice that not only makes it
 * so you only initialize your variable 1 time, but you keep your global namespace clear.
 */

var digit_name = function () {
    var names = ['zero','one','two',
        'three','four','five','six',
        'seven','eight','nine'];
        
    return function(n){
        return names[n];
    };
}();

alert(digit_name(1));

/**
 * Model Pattern
 * ========================
 */

var singleton = function () {
    var privateVariable;
    
    function privateFunction (x) {
        // private variables
    }

    return {
        firstMethod: function(a, b) {

        },
        secondMethod: function(c) {

        }
    }
}();